Application of expansion joints



Aug. 15, 1967 J. r. THORP, JR 3,

APPLICATION OF EXPANSIQN JOINTS Filed Sept. 7, 1965 4 Sheets-Sheet 1 k4,mil I Q g .f gJ n kwnswzvx:

, JAMES I T140 3 JP.

15, 1967 .1. T. THORP, JR 3,335,647

APPLICATION OF EXPANSION JOINTS Filed Sept. 7', 1965 4 Sheets-Sheet 2gar M.

Aug. 15, 196? .1. T. THORP, JR 3,335,647

APPLICATION OF EXPANSION JOINTS Filed Sept 7, 1965 4 Sheets-Sheet 7 FIG.5

M //Y YEA/7'62. JAMES I THU/2D we 3) g- 1967 J. T. THORP, JR

APPLICATION OF EXPANSION JOINTS 4 Sheets-Sheet Filed Sept.

nevrax AMES 7. THOPPJP United States Patent 3,335,647 APPLICATION OFEXPANSION JOINTS James T. Thorp, Jr., Webster Groves, Mo., assignor toLambert Engineering Company, St. Louis, Mo., a corporation of MissouriFiled Sept. 7, 1965, Ser. No. 485,160 4 Claims. (Cl. 94-51) ABSTRACT OFTHE DISCLOSURE Vehicular apparatus for implanting joint devices in unsetconcrete in which there is a set of jaws for: gripping and compressingthe resilient head of a joint device; holding it compressed while beingconcurrently vibrated and forced into the unset concrete and ejectedfrom the jaws. The jaws and their actuating equipment are mounted formovement about a horizontal axis so that the jaws may face upwardlywhile being charged with the joint device, but face downwardly whileimplanting and ejecting it.

This invention relates generally to the application of expansible andcontractible joint devices in concrete slabs, and particularly concernsan apparatus for facilitating the implanting of such joint devices inunset bodies of concrete, or the like.

Cracks resulting from expansion or contraction in concrete slabs haveever been a problem to the construction industry. The magnitude of theproblem has been said to be geometrically proportional to the magnitudeof the slab. In some cases, the best protection against multiple cracksin concrete is to induce such cracking at a few places, as by scoringthe concrete when it is yet unset, or by sawing the cut sla'b at leastpart-way through after it has set. Such control of the locus ofcracking, however, provides no protection against the likelihood ofbuckling due to expansion. In order to minimize the latter, it hasheretofore been proposed to incorporate strips of more or lesscompressible material in the concrete slab as it is poured, so that, asthe slab of concrete elongates under heat, the compressible strips willyield and accommodate the increasing dimension of the concrete. However,once such compressible material has been so compressed, it seldomresumes its initial less compressed condition, and consequently leaves acrack between it and the adjacent concrete in which moisture mayaccumulate and, under freezing conditions, damage the adjacent concrete.

More recently it has been proposed to provide a joint device having abody of highly resilient material, and an associated anchoring devicewhich may be inserted in a poured slab of concrete before the concretehas set; and if inserted with the highly resilient material in a highlycompressed state and then released from the compressing forces, the lowdegree of flowability of the concrete inhibits the resilient materialfrom resuming its initial uncompressed dimension, and accordingly whenthe concrete sets, the joint device is but partially compressed so as tobe free to expand when the concrete contracts, and free to contract whenthe concrete expands. The lastmentioned idea has met with success, butdifficulties encountered in implanting such joint devices in concretebodies of substantial dimension have militated against their use.

It is therefore an object of the present invention to provide a methodand means for implanting joint devices of the character aforesaid inpoured bodies of concrete without regard to their dimension withinpractical limits.

3,335,647 Patented Aug. 15, 1967 lCC It is a further object of theinvention to provide a method and means for facilitating and expeditingsuch an implanting operation.

Generally stated, these and other objects of the invention areaccomplished by the provision of a portable jaw bridge of such length asto extend from one side to the other of a poured concrete body, andequipping said jaw bridge with a pair of relatively movable jaws whichare so thin, or otherwise configurated, that upon insertion into a bodyof concrete which is in the process of setting, they displace so littleof the concrete that when the jaws are removed, the resilient member ofthe joint device may expand to occupy the space previously occupied bythe jaws, but still remain under substantial compression. The inventionfurther contemplates that the jaw bridge be mounted on a portablevehicle, truck, or frame in such manner that it is readily maneuvera'bleand actuatable to:

(a) Receive and compress the resilient part of the joint device,

(-b) Drive the joint device to the desired depth in the body of concretewhile maintaining the resilient part of the device compressed, and

(c) Hold the joint device in its implanted position while the jaws arewithdrawn from the body of concrete.

An illustrative embodiment of an apparatus for performing the aforesaidfunctions is shown in the accompanying drawings, in which:

FIGURE 1 is a perspective view of a joint device of a character whichtypifies those employed in accordance with the present invention;

FIGURE 2 is a fragmentary cross-sectional view showing the joint deviceof FIGURE 1 implanted in a body of concrete in accordance with thepresent invention;

FIGURE 3 is a perspective view of an implanting apparatus constructed inaccordance with the present invention, with the jaw bridge thereofpositioned to receive a joint device of the character shown in FIGURE 1;

FIGURE 4 is a view corresponding to FIGURE 3, but showing the apparatusloaded with a joint device and ready to be inserted in a slab ofconcrete which is in the charge of the joint device; and

FIGURE 8 is a view in side elevation of a portion of the jaw bridge fromthe side thereof seen in FIGURE 3,

but not seen in FIGURES 4 and 5.

While the joint device shown in FIGURES 1 and 2 forms no part of thepresent invention, an understanding of it is essential to anunderstanding of the operation and results of the apparatus to be laterdescribed. Such a joint device consists essentially of one or a pair ofmetal strips 1, preferably as long as the width of the concrete slabinto which it is to be implanted, having a flange 2 at the lower edgethereof, and embedded for at least about half of its height in a block 3of resilient material such as polyurethane foam. If separate strips 1,each having a flange 2, are employed, the strips are preferably con- Inorder to implant such a joint device in a body of concrete which is inthe process of setting, the resilient block 3 is compressed, preferablyto a thickness less than the combined spread of flange 2, and, while socompressed, is inserted into the body of concrete 4, where it expands insitu to approximately the relationship shown in FIGURE 2.

The apparatus of the present invention is intended to accomplish suchcompression and insertion of the joint device with limited displacementof the poured, but unset, concrete; and to do so with precision, as wellas with a minimum of effort.

In the embodiment shown in the drawings, the appa ratus comprises a pairof jaws and 6, which are preferably of a length such as to extendentirely across the width dimension of a slab of concrete, that is tosay, from the form at one side to the form at the other side of suchslab. The jaws 5 and 6 are preferably made with removable sections attheir respective ends, so as to be able to conform the length of thejaws to the width of slabs which, in the case of highway slabs, may varyas much as two or three feet. The adaptation of the length of the jaws 5and 6 to varying widths of concerete slab may be convenientlyaccomplished by providing a central jaw section of, say, ten feet inlength, with removable sections at each end, and replaceable endsections of different lineal dimensions.

In order to minimize the volume of concerete displaced in the process ofimplanting the joint device, it is preferable tomake the jaws 5 and 6 asthin as possible. In the embodiment shown in FIGURE 6, it will beobserved that the thickness of the jaws 5 and 6 is such that when theblock 3 is compressed for insertion, the flanges 2 of the joint deviceextend slightly beyond the outside surfaces of the jaws 5 and 6. As apractical example, the jaws 5 and 6 are constructed of steel platehaving a thickness on the order of 0.125 inch.

In the embodiment shown, the lower margins of the jaws 5 and 6 arescalloped to provide projecting fingers 7 intervened by open spaces 8,whose zeniths each preferably lie in a plane below the plane of thelower edge of block 3 when the ends of fingers 7 are engaged with theflanges 2 of a joint device, as shown in FIGURE 6. Below the plane ofthe zeniths 9, it is preferable that the openings 8 occupy at leastabout half of the total side surface area which would otherwise beincluded within the jaw plates 5 and 6. In other words, below the planeof zeniths 9, the residual metal which constitutes fingers 7 ispreferably no greater in area than that of the openings 8. Thisfacilitates ingress of the flowable concrete through the openings 8, andbehind fingers 7, into contact with strip 1 as the joint device is inthe process of implantation, so that the strip 1 will be completelyembedded in concrete up to the level of the lower end of block 3- beforejaws 5 and 6 are released and withdrawn. The openings 8 are notnecessarily of arcuate configuration, and, if desired, may be madepolygonal.

Any suitable arrangement may be provided for moving the jaws 5 and 6toward and away from each other, so as to grip and release,respectively, the joint device; to compress the block 3; and to impart adriving force to the joint device. In the form shown, the jaws 5 and 6are mounted upon a jaw bridge consisting of a plate 10, provided alongits upper edge with a series of eye bolts 11, and along its lower edgewith a series of holes 12. Each eye bolt 11 serves the dual function ofconnecting angles 13 and 14 to the plate 10, and of accommodating hingepin 15 for bracket 16. Pivotally mounted in depending relationship fromangle 14, there is a series of fluid actuated piston-cylinderorganizations 17, to the lower end of which is pivotally connected atoggle linkage consisting of links 18 and 19, the former being hinged toplate by a hinge pin 20, and the latter being hinged to bracket 16 by ahinge pin 21; and the two links 18 and 19 being hinged together and tothe rod of piston-cylinder organization 17 by a hinge pin 22. Alignedwith each of the holes 12 is a cup 23, having an adjusting screw 24 heldcaptive therein. Similarly, the lower end of each bracket 16 is providedwith a cup 25 having an adjusting screw 26 held captive therein. Theadjusting screws 24 and 26 are respectively provided with threadedpilots 27 and 28, which engage blocks 29 and 30 slidably received,respectively, within the cups 23 and 25, and, in case of the former,also received within holes 12. The block 29 is secured, as by welding,to jaw 6, and the block 30 is secured, as by welding, to the jaw 5.Thus, the adjusting screws 24 and 26, with their adjunct parts, providefor adjustment of jaws 5 and 6 relative to each other and relative toplate 10 on the one hand, and bracket 16 on the other hand; foradjusting the degree to which block 3 can be compressed; as well asproviding for quick release and attachment of separable sections of thejaw plates. It will be understood that the plate 10 is appropriatelyapertured to permit the passage of links 19 therethrough between hingepins 21 and 22.

In the condition shown in FIGURE 6, fluid pressure is being exertedwithin piston-cylinder organization 17 in order to draw hinge pin 22upwardly, and cause jaws 5 and 6 to move toward each other, so as togrip and compress block 3 of the joint device. In the condition shown inFIGURE 7, however, the fluid pressure has been applied inpiston-cylinder organization 17 so as to move hinge pin 22 downwardlyfrom the position shown in FIGURE 6 in order to release the grippingforce on block 3.

Any desired number of piston-cylinder organizations, such as 17, andtheir adjunct toggle linkages, as well as brackets 16, may be providedon the jaw bridge at appropriate spacing lengthwise thereof.

Between the jaws 5 and 6, there is mounted a stripper plate 31, whichmay be a plate of steel, or other rigid material, having a thickness onthe order of about 0.125 inch, and extending for a distance at least asgreat as the length of jaws 5 and 6. The stripper plate 31 has astraight lower edge for setting against the top end of block 3 of thejoint device. The stripper plate is also provided with apertures 32 toaccommodate the passage of links 19, and permit vertical movement of thestripper plate relative to jaws 5 and 6, as well as the other parts ofthe jaw bridge. The apertures 32 provide for movement of the stripperplate between the joint device inserting position, shown in FIG- URE 6,and the stripping position (during removal of jaws 5 and 6 from theconcrete shown in FIGURE 7). Beyond the ends of the jaws 5 and 6, thestripper 3'1 is provided, at each end thereof, with a toe plate 33. Thetoe plates 33 are for the purpose of holding the stripper plate 31 inengagement with the top end of the block 3 while the jaws 5 and 6, aswell as the balance of the jaw bridge, are moved upwardly from theposition shown in FIGURE 6 to the position shown in FIGURE 7 after thejoint device has been implanted. The stripper plate 31, when so helddown by pressure on toe plates 33, thus assures that the joint devicewill not follow the jaws 5 and 6 in their up ward movement duringwithdrawal.

The entire jaw bridge is preferably mounted upon a vehicle, or otherwisemade readily portable. In the form shown in the drawings, the vehicle isequipped with flanged wheels 34 arranged to ride upon forms of the typeconventionally employed in pouring concrete highway slabs, such asillustrated at 35. The wheels '34 are preferably mounted upon stubaxles, which are longitudinally extensible and retractable in order toadapt them to varying distances between opposite forms, such as 35.

The vehicle is preferably equipped with a source of power such as aninternal combustion engine, or an electric motor, arranged to drive asuitable source of fluid pressure 36, and provided with suitablecontrols, such as 37 and 38, for controlling the flow of pressure fluidto piston-cylinder organizations 17 and other fluid actuated deviceslater to be described. In addition, the vehicle shown in FIGURES 3, 4and 5 includes a storage box 39, within which may be kept a workingsupply of joint devices, as

well as removable and replacement sections of jaws 5 and 6, togetherwith such other tools and accessories as may be desirable.

The jaw bridge is mounted upon the vehicle through a pair of offsethinges 40, each connected at one end thereof to the angles 13 and 14,and at the other end through a hinge pin 41 to a clamp 42, which issecured to move with a cylinder 43 of a piston-cylinder combinationwhose piston rod 44 is fixedly connected to the carriage of the vehiclethrough a bracket 45. One such hinged, and one such piston-cylindercombination, are preferably provided near each end of the jaw bridge.

The hinges 40 provide for movement of the jaw bridge between thecharging position shown in FIGURE 3 (where the jaws 5 and 6 are at thetop side of the jaw bridge) and the operative or implanting positionshown in FIG- URES 4 and 5 (where the jaws 5 and 6 are on the lower sideof the jaw bridge).

In the embodiment shown, the jaw bridge is moved between the positionshown in FIGURE 3 and the position shown in FIGURE 4 by manualmanipulation of the handle bars 46, one set of which is provided at eachend of the jaw bridge, but it will be understood that when and ifdesired, such movement can be accomplished by power-driven equipment.

When in the position shown in FIGURE 3, with the pressure onpiston-cylinder combinations 17 relaxed, a joint device may be readilyinserted between the jaws 5 and 6, so that upon energization ofpiston-cylinder combination 17, the resilient block 3 of the jointdevice will be engaged and compressed by movement of the jaws towardeach other. When sufficiently compressed for implanting in the concrete,the joint device moves with the jaw bridge about the hinges 40 until itassumes the position shown in FIGURE 4, and is then lowered by controlof the fluid pressure within piston-cylinder combination 43 until theflanges 2 of the joint device are at, or near, contact with the surfaceof the poured but unset concrete slab. Upon reaching this position, thefluid pressure within piston-cylinder combination 43 may be released, sothat the weight of the jaw bridge tends to drive the joint device, aswell as the jaws 5 and 6, into the concrete slab. This driving actionmay be promoted by one, two, or all of three means: first, by downwardpressure on the handle bars 46; second, by operation of a vibrator 47midway of the length of the jaw bridge on flanges 13 and 14; third, bythe admission of pressure fluid into piston-cylinder combination 43 in adirection such as to drive hinge 40 downwardly. The vibrator 47 ispreferably fluid-pressure operated, and is provided with a driven rotorhaving an axis which extends substantially parallel with the lengthwisedimension of the jaw bridge, and whose center of gravity is eccentricwith respect to the axis of rotation, so as to produce vibrations havingan amplitude on the order of an eighth of an inch or less.

When the jaw bridge, with its engaged joint device, has moved downwardlyfor a distance suflicient to implant the joint device in the concrete ata depth such that the top of the compressed resilient block 3 isreasonably close to the surface of the concrete slab, as shown, forexample, in FIGURE 6, the pressure in piston-cylinder combination 17 maybe relaxed, but preferably not sufficient to actively force jaws 5 and 6apart to a substantial degree. While the clamping action of the jaws isthus relaxed, attendants at opposite ends of the jaw bridge may each puta foot upon the toe plates 33, and then either lift the jaw bridgemanually, or admit pressure fluid into cylinders 43 in a manner such asto cause them to lift the jaw bridge vertically. The relaxation of thegrip between jaws 5 and 6, on the one hand, and resilient block 3, onthe other hand, releases stripper 31 for vertical movement relative tothe jaws 5 and 6, but the placing of each attendants foot upon the toeplates 33 assures that the stripper plate 31 will not move upwardly asthe jaws 5 and 6 move upwardly to resilient block 3 of the joint device.

Such relative movement of the stripper plate 31 relative to the jaws islimited by the expanse of apertures 32 in the stripper plate. While theprojection of links 19 through such apertures can, if desired, be reliedupon to so limit such relative movement, it is preferable to provide, inplate 10, a series of abutments 48, which are arranged to contact theupper edge of apertures 32 when the stripper plate has reached thedownward extreme of its movement relative to jaws 5 and 6.

In the course of raising the jaw bridge as last described, while thestripper plate is held in position, as shown in FIGURE 7, where itslower edge rests upon the top of resilient block 3, the joint device isheld in its implanted position by the dead weight of the stripper plate,plus, if need be, the resistance of implanted human feet upon the toeplates 33. Once the jaw bridge is elevated to the point where theextremities of fingers 7 in the jaws 5 and 6 are clear of the surface ofthe concrete, the jaw bridge may be rotated from the position shown inFIGURE 4 to the position shown in FIGURE 3, where it is ready to receiveanother joint device, and proceed with the implantation thereof at anappropriate distance from the locus of its last operation.

From the foregoing description, those skilled in the art shouldunderstand that the invention accomplishes its objects, and provides aconvenient, economical and easily operated mode of implanting jointdevices of the character described in slabs of concrete which is in theprocess of setting, all without unduly disturbing the concrete, orinhibiting its flow into anchorage about the flanges 2 of the jointdevice. If the concrete is in a condition of relatively high flowabilitywhen the jaws 5 and 6 are withdrawn from it, the convergence of theconcrete upon opposite sides of the compressed block 3 through openings8, while the block is still held compressed by fingers 7, tends toprevent expansion of the portions of the block engaged by fingers 7 fromsubstantial recovery of their naturally expanded state as the fingersare drawn past them. When the resilient block 3 is made of slow recoverypolyurethane material, the rate of convergence of the concrete, even ina relatively low state of flowability, is nonetheless sufficiently rapidto arrest expansion of block 3 before it has recovered substantiallyfrom its fully compressed state. Thus, the ultimate result is not onlyto provide a secure anchorage of the joint member by the convergence offlowable concrete about it before relaxation of the grip of jaws 5 and6, as well as afterwards, but also to obtain a susbtantially watertightjoint between the compressed head 3 of the joint device and thecontiguous bodies of concrete.

While one complete embodiment of the invention has been disclosed indetail, such disclosure is merely illustrative of the invention, and notintended as a limitation upon it. Those skilled in the art will readilyperceive of modifications and variations which fall within the spirit ofthe invention, and such are intended to be within the spirit of theappended claims.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. Apparatus for implanting joint devices having resilient heads anddepending anchors in a slab of unset concrete, comprising a vehicle oflength suflicient to bridge the width of said slab, a jaw bridgeextending lengthwise of said vehicle, a hinge connecting said jaw bridgeto said vehicle, said hinge having an axis extending lengthwise of saidvehicle, means mounting said hinge axis for vertical movement relativeto one of (a) said vehicle, and

(b) said jaw bridge, said jaw bridge having a pair of relatively movableopposite jaws, means mounting said jaws on said jaw bridge for movementtoward each other to grip and compress the resilient head of a jointdevice and for movement away from each other to release said resilienthead, and means for vibrating said jaw bridge.

2. The combination of claim 1 having a plurality of fluid-pressureresponsive means for driving said jaws int o and out of compressingrelationship with said resilient head.

3. The combination of claim 1 having a stripper plate between said jaws,and means for moving said jaw bridge vertically relative to saidstripper.

4. The combination of claim 1 wherein said jaws have a plurality ofspaced fingers for engaging said joint device below said resilient head,and the space between adjacent ones of said fingers is at least as greatas the area of a finger.

- References Cited UNITED STATES, PATENTS Kovando 94--51 Carnes 9451Brown 94-51 X Cooper et a1. 9418 Worson 9451 Middlestadt 9451 JACOB L.NACKENOFF, Primary Examiner.

1. APPARATUS FOR IMPLANTING JOINT DEVICES HAVING RESILIENT HEADS ANDDEPENDING ANCHORS IN A SLAB OF UNSET CONCRETE, COMPRISING A VEHICLE OFLENGTH SUFFICIENT TO BRIDGE THE WIDTH OF SAID SLAB, A JAW BRIDGEEXTENDING LENGTHWISE OF SAID VEHICLE, A HINGE CONNECTING SAID JAW BRIDGETO SAID VEHICLE, SAID HINGE HAVING AN AXIS EXTENDING LENGTHWISE OF SAIDVEHICLE, MEANS MOUNTING SAID HINGE AXIS FOR VERTICAL MOVEMENT RELATIVETO ONE OF (A) SAID VEHICLE, AND